VH1's 'Celebrity Rehab' and A&E's 'Intervention' series are causing some professionals in the rehab field to worry that such programs about addiction are exploiting patients at their most vulnerable.

Leif Garrett didn't want to go to rehab — or at least not "Celebrity Rehab."

"I didn't want to have a camera stuck in my face while I was trying to kick," said Garrett, the 1970s teen idol once as famous for his singing and acting as his sun-kissed mane of blond hair. "I thought, 'It's nobody's freaking business.' But I finally came to the realization: It's everybody's business, because it's been in the papers. Instead of paying to go to rehab, why not get paid for it? And show the world, at the same time, that I am no longer using?"

Garrett, now 49, struggled with substance abuse from a young age. But his troubles escalated last February, when he was arrested on suspicion of possessing black tar heroin, according to police. His booking photograph soon appeared in tabloids and on the Internet. (In October, he was ordered to enter a drug rehab program that will not be part of any reality show.)

After the arrest, he was approached numerous times by VH1, the network that produces the reality show "Celebrity Rehab "With Dr. Drew," to see if he might consider joining a cast comprising mostly of B-list actors and reality television stars at a Pasadena rehabilitation center run by Dr. Drew Pinsky. There, members of the group would be forced to tackle his or her addictions —- pain pills, alcohol, marijuana, even love — while a camera crew documented the emotional journey.

Being a part of "Celebrity Rehab," Garrett concluded, was the best shot he had at regaining sobriety and his reputation. Most of the cast members on the fourth season of the show — which includes actor Eric Roberts and Tiger Woods' alleged mistress Rachel Uchitel — said a similar line of thinking propelled them to participate: What do I have to lose?

But some professionals in the rehab field worry that programs about addiction — a genre that also includes HBO's documentary series "Addiction" and A&E's popular "Intervention," now in its 10th season — are exploiting patients in their most vulnerable moments. Sure, participants are getting free treatment, but there's also a concern that cameras interfere with the process.

VH1 says "Celebrity Rehab" is designed to help people, but good television also requires intense drama. And since many of the participants are celebrities hoping to rescue their image, playing to the camera may distract them from focusing fully on therapy.

"People who are sharing the most intimate details of their life are going to change the way they relate to their therapist on camera," said Dr. David Sack, the chief executive of Malibu's Promises Treatment Center. "It becomes a performance — not treatment."

"Intervention," meanwhile, centers on noncelebrity addicts. The show, which has become one of A&E's most successful programs since its inception in 2005, trails those in particularly dire situations — in one episode, a man who is a crystal methamphetamine addict is also shown snorting OxyContin and is described as having snorted up to 40 of the pills a day.

The subjects are told they are being filmed for a TV documentary, but unlike "Celebrity Rehab" patients, they are not paid to participate. What they don't know is that friends and family are secretly planning an intervention, during which they are asked to go to treatment. If they agree, A&E finds rehabilitation centers that will cover the bill for a minimum 90-day stay for the patient.

The appeal of both programs relies at least partly in voyeurism. On "Celebrity Rehab," cameras trail the cast members to therapy sessions. They capture the fights that inevitably transpire between addicts and often catch patients vomiting or writhing in pain from withdrawal.

In this season's opening episode, Janice Dickinson, a former supermodel and reality TV star, had been weaned off of benzodiazepines, which resulted in a massive panic attack. Sobbing to one of the hospital's staff members, she revealed she was contemplating going to the bathroom to hang herself. The moment was teased endlessly in previews leading to the premiere.

It's exactly the kind of moment that Sack says those who sign up for the show don't realize might later haunt them.

"Our concern is that people who are in the throes of an addiction should not be signing a release for something that will be shown on TV over and over," he explained. Most reality television shows, he explained, require subjects to sign an irrevocable release contract which states that all footage filmed of them may be used on air, even if they change their mind midway.

Garrett, for one, insisted he was not "coerced" into signing a contract to appear on "Celebrity Rehab." "I was a functioning addict," he explained. "I'd made many decisions in business meetings outside of doing this show."